Weeds. Weeds. Weeds. One of the main reasons producers consider returning to tillage after starting a low disturbance seeding system is the trouble they have with one or more problematic weeds. This is one of the most common complaints I have heard on my numerous field calls in the last few years. It may be dandelions, tansy, foxtail barley, narrow-leaf hawk's-beard or any of a host of others. The reasoning seems logical: "I didn't have the problem when I used to cultivate. Therefore, the way to control it is to return to tillage."
But remember: weed control is one of the pillars of direct seeding. A common thread among these producers considering a return to tillage has been the lack of a systems approach. They don't use all the tools they have in their toolbox or should have in their toolbox.
It must be human nature that we are always trying to keep things constant. The sun rises in the east and sets in the west, my weed spectrum remains stable and life is good. However when the weed spectrum changes, as it will when we make a significant management change such as moving to a low disturbance seeding system, some people see it simply as a challenge which will be overcome, while others view it as an end in it's self. Producers such as the latter tend to revert to the last management technique that they felt was successful. Is this wrong? Not necessarily. Everyone has a different comfort level associated with farming risks. It is important each producer determine this level. It has long being recognized that direct seeding or low disturbance seeding possesses a higher risk. The type of management implemented on the farm will dictate whether the risk is justified. Equally important, however, is continuing to be a steward of the land.
Producers who are successful at making the management change to a lower disturbance system are individuals who make wholesale changes in every aspect of their farming operation. They are continually monitoring their weed spectrum. They are upgrading their skills at weed identification and other management techniques. They are constantly learning about the growth habit of the new weed spectrum. They are using as many of the tools from the toolbox that are available to them.
So what tools should be in your low-disturbance toolbox? Pre-harvest, post-harvest, and pre-seeding applications of glyphosate or fall applications of 2,4-D are important. You may not need to do them every year, but having them in your toolbox and implementing them into your crop plans are both necessary.
Yes a plan. That should also be in your toolbox, near the top I might add. It's the old adage, "Most people don't plan to fail, they fail to plan." You may have had things well mapped out with your tillage operation, but have you developed a thorough strategy for your new low-disturbance operation? Developing a complete plan is important, and remember to keep an open mind.
Your toolbox should also include a more diverse crop rotation. What crops do you presently grow and what crops could you potentially grow?
For example, would forages be an option? Even if you're not into cattle, forages could benefit a neighbour. In turn, the manure from his livestock operation would likely be a benefit to your soil. Forages have long been recognized for their many beneficial characteristics, particularly their ability to suppress weed growth. Forage can provide a viable alternative to herbicide inputs. Work by Martin Entz in Manitoba has shown reduction in wild oats, Canada thistle, wild mustard and cleavers after as little as three years of alfalfa in the rotation. In fact wild oat populations in wheat following alfalfa were equal to wheat which had been sprayed with a wild oat herbicide. This is just one example of forage's potential for weed control, and a good example of the importance of a diverse crop rotation.
Including forages in your rotation also plays a significant role in alternating seeding dates. This is another vital tool for any seeding system. One of the easiest ways to select for a specific weed spectrum is to do the same things every year. If we seed particular fields either first or last every year we are selecting for a specific problem. The inclusion of forages allows us to diverge away from this constant. With forages we have competition throughout the growing season.
Having a diverse rotation of annual crops often allows the seeding operations to occur naturally at different times. The inclusion of fall seeded crops adds further diversity as to when crops are seeded. Crops like winter wheat, fall rye, triticale or possibly fall-seeded canola alter the time frame for when seeding takes place. They can also alter the time frame for when pre-seeding or in-crop herbicide applications take place. These alternatives help to keep the weed spectrum off balance. Throwing a curve at the weed spectrum is the key to successfully keeping specific weeds from becoming a problem.
Another important tool is a re-examination of summerfallow. For many years we believed that we had to include summerfallow in the rotation to allow the land to have a rest from crop production. However, there are no examples in nature that adhere to this adage. In general, nature covers the land in some type of vegetation at all times. A diverse rotation that includes pulses, oilseeds, cereals and even forages is important for keeping not only the weed spectrum in check, but also crop diseases and insects. As well a constant cover on the land helps to protect it from erosion. Remember the old adage "a change is as good as a rest".
Finally your toolbox should have some different approaches to fertilizer application. Fertilize your crop and not the weeds. Locate the fertilizer so the emerging crop has the advantage over the weeds. Fall banding, double shoot openers, mid-row coulters or coated fertilizer gives us the opportunity to put our crop one up on the weeds. Broadcast applications of fertilizer tend to give the advantage to the weeds. But remember that it is important to select the type of fertilizer placement that works with your operation.
So do we need to revert to tillage? In most instances the answer is no. With a good plan in place, tillage is not likely required. However, tillage can always be used as a last resort. It is after all, another tool we have in our toolbox. But perhaps it could remain buried a bit longer while you plan out your tools of the new millennium.